Flux syntax problem: calculations on two measurements with slightly different time stamps

1

Hi experts,

I try to calculate the sum of two values from two independent measurements using Flux on an InfluxDB 2.7. Currently,I am trying to re-use code where I successfully summed values from ONE measurement:

from(bucket: "Stromverbrauch")
  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)
  |> filter(fn: (r) => r["_measurement"] == "meas1" or r["_measurement"] == "meas2")
  |> filter(fn: (r) => r["_field"] == "data1" or r["_field"] == "data2") # note: data1 from meas1, data2 from meas2
  |> pivot(rowKey: ["_time"], columnKey: ["_field"], valueColumn: "_value")
  |> map(fn: (r) => ({r with _value: r.meas1 + r.meas2}))
  |> drop(columns: ["meas1", "meas2""])
  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: true)
  |> yield(name: "mean")

This query yields no data, which is due to the fact that the is a time difference of 2 seconds between equivalent data points from meas1 and meas2.

Reading the Flux documentation I figured that it should be possible to use timeShift(...) to move a data point. However, I am not sure how this could be done in my scenario, where I only want to shift ONE of the two data sets.

So maybe you know how to achieve my goal? Thanks in advance

2

truncateTimeColumn() function | Flux 0.x Documentation (influxdata.com)

time shift will shift all the data points in the series. with the same offset.

truncate time by the other hand can be used to round the timestamps to the same unit of time, i.e. units of 10s